Laminate improving slippage of hardcoat layer

ABSTRACT

There is provided a laminate comprising a hard coat layer having the outermost surface to which slipperiness has been imparted. The laminate comprises a transparent substrate and a hard coat layer provided on said transparent substrate. The hard coat layer is formed of a cured product of a composition comprising a fluorine-modified urethane acrylate and/or a polydimethylsiloxane having a polyether-modified acryl or polyether group.

TECHNICAL FIELD

The present invention relates to a laminate, particularly a (optical)laminate for use in displays such as CRTs and liquid crystal panels.

BACKGROUND ART

Most of laminates, especially displays such as liquid crystal panels,have a construction including a luminous body, a reflector plate, apolarizing plate, an anti-dazzling film, a hard coat layer, and atransparent substrate. In particular, a method commonly used in theproduction of a transparent substrate provided with a hard coat layerincludes the steps of: unwinding a transparent substrate in a roll form;forming a hard coat layer on the surface of the transparent substrate;and then winding the assembly, comprising the transparent substratehaving a hard coat layer on its surface, into a roll while interposing apolyethylene terephthalate film having a small thickness and a smallwidth as a side tape into between the hard coat layer and thetransparent substrate from the viewpoint of preventing adhesion betweenthe hard coat layer and the transparent substrate (a roll-to-rollmethod). General contents of the roll-to-roll method are disclosed inJapanese Patent Laid-Open No. 335559/2000. However, it has been pointedout that the use of the side tape is an obstacle to high-speedproduction and an increase in production cost. Further, it has also beenoften pointed out that continuous production of the display in the nextstep becomes difficult.

On the other hand, the addition of a silicone oil as a leveling agent tothe hard coat layer has been proposed. However, when the material per sefor hard coat layer formation is curable and slippery, this nature isconvenient for handling.

Accordingly, at the present time, a laminate, in which any silicone oilis not used and a product prepared by unwinding a transparent substratein a roll form and forming a hard coat layer on the surface of thetransparent substrate as such can be wound into a roll without the needto use any side tape, has eagerly been desired.

SUMMARY OF THE INVENTION

The present inventors have now found that the addition of a curablemodified acrylate represented by a specific chemical formula as amaterial for hard coat layer formation can realize the formation of ahard coat layer having slipperiness and that the formed laminate can beproductized in a roll form without the need to use any side tape. Thepresent invention has been made based on such finding.

Accordingly, an object of the present invention is to provide animproved laminate in which, when slipperiness is imparted to a hard coatlayer followed by winding of the laminate into a roll, the adhesionbetween the hard coat layer and the transparent substrate has beensuppressed.

Thus, according to the present invention, there is provided a laminatecomprising

-   -   a transparent substrate and a hard coat layer provided on said        transparent substrate,    -   said hard coat layer being formed of a cured product of a        composition comprising a fluorine-modified urethane acrylate        and/or a polydimethylsiloxane represented by formula (I):        wherein    -   A represents a polyether-modified acryl group or a polyether        group.

DETAILED DESCRIPTION OF THE INVENTION

Laminate

1) Hard Coat Layer

The hard coat layer in the present invention utilizes afluorine-modified urethane acrylate and/or a polydimethylsiloxanerepresented by formula (I). This is a material for constituting the hardcoat layer and can function to impart slipperiness to the hard coatlayer.

The fluorine-modified urethane acrylate is such that hydrogen atoms inurethane acrylate have been replaced by a fluorine atom, preferably suchthat all the hydrogen atoms in the urethane acrylate have been replacedby a fluorine atom. The fluorine-modified urethane acrylate is acommercially available product, and example thereof include MCF-350SF(manufactured by Dainippon Ink and Chemicals, Inc.).

The polydimethylsiloxane represented by formula (I) wherein A representsa polyether-modified acryl group may be a commercially availableproduct, and examples thereof include BYK-UV3500 (manufactured byBik-Chemie). Further, the polydimethylsiloxane represented by formula(I) wherein A represents a polyether group may be a commerciallyavailable product, and examples thereof include BYK-UV3510 (manufacturedby Bik-Chemie).

The amount of the fluorine-modified urethane acrylate and/orpolydimethylsiloxane represented by formula (I) added is not less than0.1% by weight and not more than 5% by weight based on the total weightof the hard coat layer. Preferably, the lower limit of the additionamount is 0.15% by weight, and the upper limit of the addition amount is1% by weight. More preferably, the lower limit of the addition amount is0.2% by weight, and the upper limit of the addition amount is 1% byweight.

Basic Material

In the present invention, the hard coat layer may contain the above twocompounds and additional other basic materials, for example, an ionizingradiation curing composition such as a UV curing compound. Examples ofpreferred curing compositions include pentaerythritol acrylate “PETA”and dipentaerythritol hexaacrylate “DPHA.” A photopolymerizationinitiator can be used in forming the hard coat layer, and specificexamples thereof include 1-hydroxy-cyclohexyl-phenyl-ketone. Thiscompound is commercially available, for example, under the tradenameIrgacure 184 from Ciba Specialty Chemicals, K.K.

The amount of the basic material added is not less than 80% by weightand not more than 99% by weight based on the total weight of the hardcoat layer. Preferably, the lower limit of the addition amount is 85% byweight, and the upper limit of the addition amount is 98% by weight.More preferably, the lower limit of the addition amount is 90% byweight, and the upper limit of the addition amount is 95% by weight.

Optional Materials

In the laminate according to the present invention, the hard coat layermay contain an antistatic agent (an electrically conductive agent)and/or an anti-dazzling agent.

Antistatic Agent

Specific examples of antistatic agents include electrically conductivefine particles of a metal or a metal oxide or an organic compound, forexample, fine particles of antimony-doped indium tin oxide (hereinafterreferred to as “ATO”), indium tin oxide (hereinafter referred to as“ITO”), and organic compounds which had been surface treated with goldand/or nickel.

The amount of the antistatic agent added is not less than 5% by weightand not more than 70% by weight based on the total weight of the hardcoat layer. Preferably, the lower limit of the addition amount is 15% byweight, and the upper limit of the addition amount is 60% by weight.More preferably, the lower limit of the addition amount is 25% byweight, and the upper limit of the addition amount is 50% by weight.

Anti-Dazzling Agent

Specific examples of anti-dazzling agents include plastic beads,particularly preferably transparent plastic beads. Specific examples ofplastic beads include styrene beads (refractive index 1.59), melaminebeads (refractive index 1.57), acryl beads (refractive index 1.49),acryl-styrene beads (refractive index 1.54), polycarbonate beads, andpolyethylene beads. Preferred plastic beads include styrene beads.

The particle diameter of the plastic beads is not less than 0.5 μm andnot more than 15 μm. Preferably, the lower limit of the particlediameter is 3 μm, and the upper limit of the particle diameter is 6 μm.Particle diameters falling within the above-defined range areadvantageous in that the light diffusing effect is high, satisfactoryanti-dazzling properties can be imparted, the internal haze value can beincreased, and dazzling of images can be satisfactorily improved.

The amount of the plastic beads added is not less than 3% by weight andnot more than 30% by weight based on the total weight of the hard coatlayer. Preferably, the lower limit of the addition amount is 5% byweight, and the upper limit of the addition amount is 20% by weight.More preferably, the lower limit of the addition amount is 8% by weight,and the upper limit of the addition amount is 15% by weight. Theaddition amount falling within the above-defined range is advantageousin that the effect of diffusing light is high, the sharpness of thetransmitted image is increased, and dazzling of images can besuppressed.

When plastic beads are added, inorganic fillers such as silica may beadded. The addition of the inorganic filler can suppress the settling ofplastic beads added to the resin component for forming the hard coatlayer.

The particle diameter of the inorganic filler is preferably not lessthan 0.5 μm and not more than 5 μm. The amount of the inorganic filleradded is not less than 3% by weight and not more than 30% by weightbased on the total weight of the hard coat layer. Preferably, the upperlimit of the addition amount is 15% by weight. When the particlediameter or addition amount of the inorganic filler falls within theabove-defined range, settling of the plastic beads can be effectivelyprevented.

When the plastic beads or inorganic fillers have been added, a preferredmethod is to satisfactorily mix them with the resin component forconstituting the hard coat layer to prepare a homogeneous dispersionwhich is then coated onto the transparent substrate.

Antistatic Agent and Anti-Dazzling Agent

In another embodiment of the present invention, both the antistaticagent and the anti-dazzling agent may be added. The details of theantistatic agent and the anti-dazzling agent may be the same as those asdescribed above.

Formation of Hard Coat Layer

The hard coat layer may be formed by mixing the above two acrylatecompounds and optionally an antistatic agent and an anti-dazzling agentin a suitable solvent, for example, toluene, xylene, cyclohexane, ethylacetate, butyl acetate, propyl acetate, MEK, and MIBK, to prepare aliquid composition which is then coated onto a transparent substrate.

In a preferred embodiment of the present invention, a leveling agent,for example, a fluorine or silicone leveling agent, is added to theliquid composition. In the liquid composition with the leveling agentadded thereto, upon coating or drying of the coating, the inhibition ofcuring by oxygen on the surface of the coating can be effectivelyprevented, and, at the same time, the anti-scratch effect can beimparted. The leveling agent is preferably utilized in transparentsubstrates in a film form where heat resistance is required (forexample, triacetylcellulose).

Methods usable for coating the liquid composition include roll coating,Mayer-bar coating, and gravure coating. After coating of the liquidcomposition, drying and ultraviolet curing are carried out.

Specific examples of ultraviolet light sources include light sourcessuch as ultrahigh pressure mercury lamps, high pressure mercury lamps,low pressure mercury lamps, carbon arc lamps, blacklight fluorescentlamps, and metal halide lamps. The wavelength of the ultraviolet lightmay be in a wavelength range of 190 to 380 nm. Specific examples ofelectron beam sources include various electron beam accelerators, forexample, Cockcroft-Walton, van de Graaff, resonance transformer,insulated core transformer, linear, dynamitron, and high-frequencyelectron beam accelerators.

The thickness of the hard coat layer is not less than 1 μm and not morethan 30 μm, preferably not less than 2 μm and not more than 10 μm. Whenthe transparent substrate is a plate form, the thickness may exceed theabove upper limit of the thickness.

2) Transparent Substrate

Preferably, the transparent substrate is transparent, smooth, andresistant to heat and has excellent mechanical strength. Specificexamples of the material for constituting the transparent substrateinclude thermoplastic resins such as triacetylcellulose, polyester,cellulose triacetate, cellulose diacetate, cellulose acetate butyrate,polyester, polyamide, polyimide, polyether sulfone, polysulfone,polypropylene, polymethyl pentene, polyvinyl chloride, polyvinyl acetal,polyether ketone, polymethyl methacrylate, polycarbonate, andpolyurethane. Preferred are triacetylcellulose, polyesters, andcellulose triacetate.

In the present invention, these thermoplastic resins are used as a thin,highly flexible film. Depending upon embodiments where curing propertiesare required, plates of thermoplastic resins or glass plates may also beused.

The thickness of the transparent substrate is not less than 20 μm andnot more than 300 μm. Preferably, the upper limit of the thickness is200 μm, and the lower limit of the thickness is 30 μm. When thetransparent substrate is in a plate form, the thickness may exceed theabove upper limit.

In the formation of the hard coat layer on the transparent substrate,the transparent substrate may previously be subjected to physicaltreatment such as corona discharge treatment and oxidation treatment, ormay previously be coated with a coating composition called an anchoringagent or a primer from the viewpoint of improving the adhesion.

3) Optional Layer

In another aspect of the present invention, there is provided a laminatehaving a basic construction comprising a transparent substrate and ahard coat layer provided on the upper surface of the transparentsubstrate, wherein at least one layer selected from the group consistingof an antistatic layer, an anti-dazzling layer, and a refractive indexlayer is provided.

a. Antistatic Layer

The antistatic layer (electrically conductive layer) is preferablyformed on the upper surface of the hard coat layer. Specific examples ofmethods usable for forming an antistatic layer are one in which avapor-deposited film is formed by vapor-depositing or sputtering anelectrically conductive metal, an electrically conductive metal oxide orthe like onto the upper surface of a hard coat layer, and one in which acoating is formed by a resin composition comprising electricallyconductive fine particles dispersed in a resin.

When the antistatic layer is formed as a vapor-deposited film, examplesof electrically conductive metals or electrically conductive metaloxides include antimony-doped indium tin oxide (hereinafter referred toas “ATO”) and indium tin oxide (hereinafter referred to as “ITO”).

The thickness of the vapor-deposited film as the antistatic layer is notless than 10 nm and not more than 200 nm. Preferably, the upper limit ofthe thickness is 100 nm, and the lower limit of the thickness is 50 nm.

Specific examples of electrically conductive fine particles usable informing the antistatic layer as a coating may be the same as thosedescribed above in connection with the antistatic agent. The amount ofthe electrically conductive fine particles added is not less than 5% byweight and not more than 70% by weight based on the total weight of theantistatic layer. Preferably, the upper limit of the addition amount is60% by weight, and the lower limit of the addition amount is 15% byweight.

The resin for dispersing electrically conductive fine particles ispreferably transparent, and three types of resins, that is, ionizingradiation curing resins which are curable by ultraviolet light orelectron beam irradiation, mixtures of ionizing radiation curing resinswith solvent drying type resins, and heat-curing resins, may bementioned as specific examples of this resin.

Ionizing Radiation Curing Resin

Specific examples of ionizing radiation curing resins include resinshaving an acrylate functional group, and examples thereof includerelatively low-molecular weight polyester resins, polyether resins,acrylic resins, epoxy resins, urethane resins, alkyd resins, spiroacetalresins, polybutadiene resins, and polythiol-polyene resins, oligomers orprepolymers of (meth)acrylate or the like of polyfunctional compounds,such as polyhydric alcohols, and ionizing radiation curing resinscontaining a reactive diluent. Reactive diluents usable herein includemonofunctional monomers, such as ethyl (meth)acrylate, ethylhexyl(meth)acrylate, styrene, methyl styrene, and N-vinylpyrrolidone, andpolyfunctional monomers, for example, polymethylolpropanetri(meth)acrylate, hexanediol (meth)acrylate, tripropylene glycoldi(meth)acrylate, diethylene glycol di(meth)acrylate, pentaerythritoltri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,6-hexanedioldi(meth)acrylate, or neopentyl glycol di(meth)acrylate.

When the ionizing radiation curing resin is used as the ultravioletcuring resin, the use of a photopolymerization initiator is preferred.Specific examples of photopolymerization initiators includeacetophenones, benzophenones, Michler's benzoyl benzoate, α-amyloximeesters, tetramethylthiuram monosulfide, and thioxanthones. Further, theuse of a mixture of the photopolymerization initiator with aphotosensitizer is preferred. Specific examples thereof includen-butylamine, triethylamine, and poly-n-butylphosphine.

Solvent Drying Type Resin

Main solvent drying type resins usable as a mixture with the ionizingradiation curing resin are thermoplastic resins which are commonlydescribed and used in the art. The addition of the solvent drying typeresin can effectively prevent defects of coating of the coated face.

In a preferred embodiment of the present invention, when the materialfor the transparent substrate is a cellulosic resin such as TAC,specific examples of preferred thermoplastic resins include cellulosicresins, for example, nitrocellulose, acetylcellulose, cellulose acetatepropionate, and ethylhydroxyethylcellulose. The use of the cellulosicresin can improve the adhesion between the transparent substrate and theantistatic layer and the transparency.

Heat Curable Resins

Specific examples of heat curable resins include phenolic resins, urearesins, diallyl phthalate resins, melamine resins, guanamine resins,unsaturated polyester resins, polyurethane resins, epoxy resins,aminoalkyd resins, melamine-urea co-condensed resins, silicone resins,and polysiloxane resins. When heat curable resins are used, ifnecessary, crosslinking agents, curing agents such as polymerizationinitiators, polymerization accelerators, solvents, viscosity modifiersand the like may be further added.

The thickness of the coating as the antistatic layer is not less than0.05 μm and not more than 2 μm. Preferably, the lower limit of thethickness is 0.1 μm, and the upper limit of the thickness is 1 μm.

When the coating is formed as the antistatic layer, a liquid compositioncontaining a mixture of the above resin with the above electricallyconductive fine particles can be coated by a coating method such as rollcoating, Mayer-bar coating, or gravure coating. After coating of theliquid composition, drying and ultraviolet curing are carried out.

The ionizing radiation curing resin composition is cured by irradiationwith an electron beam or ultraviolet light. In the case of electron beancuring, for example, electron beams having an energy of 100 to 300 KeVare used. On the other hand, in the case of ultraviolet curing, forexample, ultraviolet light emitted from light sources such as ultrahighpressure mercury lamps, high pressure mercury lamps, low pressuremercury lamps, carbon arc, xenon arc, and metal halide lamps, areutilized.

Preferably, the antistatic layer is formed so as to have a=surfaceresistivity of not more than 5×10⁷ Ω/□.

b. Anti-Dazzling Layer

The anti-dazzling layer is preferably formed on the upper surface of thehard coat layer or the antistatic layer. The anti-dazzling layer may beformed by coating a liquid composition comprising an anti-dazzling agentdispersed in the resin. The anti-dazzling agent, the resin, the coatingmethod and the like may be the same as those described above.

The thickness of the anti-dazzling layer is not less than 0.5 μm and notmore than 10 μm. Preferably, the lower limit of the thickness is 1 μm,and the upper limit of the thickness is 7 μm.

In a preferred embodiment of the present invention, an antistaticlayer/anti-dazzling layer formed of a mixture of an antistatic agentwith an anti-dazzling agent may be provided.

c. Refractive Index Layer

The refractive index layer is preferably formed on the upper surface ofthe anti-dazzling layer. Preferably, the refractive index layer has alower refractive index than the anti-dazzling layer. In a preferredembodiment of the present invention, the anti-dazzling layer has arefractive index of not less than 1.5, and the refractive index of therefractive index layer is less than 1.5, preferably not more than 1.45.

A preferred embodiment of the laminate according to the presentinvention comprises a transparent substrate and a transparentelectrically conductive layer (the refractive index thereof being notmore than that of the anti-dazzling layer), an anti-dazzling layer(refractive index: not less than 1.50), and a refractive index layer(refractive index: less than 1.5). Since the laminate is in contact withan air layer (refractive index: 1.0), the reflection can be efficientlyprevented. In particular, the effect of preventing reflection attainedby stacking the refractive index layer having a lower refractive indexthan the refractive index of the anti-dazzling layer can be enhanced.

The thickness of the refractive index layer is not less than 20 nm andnot more than 800 nm. Preferably, the upper limit of the thickness is400 nm, and the lower limit of the thickness is 50 nm.

Specific examples of the material for constituting the refractive indexlayer include silicone-containing vinylidene fluoride copolymers. Anexample thereof is a resin composition comprising: 100 parts by weightof a fluorine-containing copolymer having a fluorine content of 60 to70% by weight prepared by copolymerizing a monomer compositioncontaining 30 to 90% by weight of vinylidene fluoride and 5 to 50% byweight of hexafluoropropylene; and 80 to 150 parts by weight of apolymerizable compound containing an ethylenically unsaturated group.

An example of the fluorine-containing copolymer is a copolymer preparedby copolymerizing a monomer composition containing vinylidene fluorideand hexafluoropropylene. The content of vinylidene fluoride and thecontent of hexafluoropropylene in this monomer composition are 30 to 90%by weight, preferably 40 to 80% by weight, particularly preferably 40 to70% by weight, and 5 to 50% by weight, preferably 10 to 50% by weight,particularly preferably 15 to 45% by weight, respectively. This monomercomposition may further contain 0 to 40% by weight, preferably 0 to 35%by weight, particularly preferably 10 to 30% by weight oftetrafluoroethylene.

The monomer composition for preparing the fluorine-containing copolymermay if necessary contain, for example, not more than 20% by weight,preferably not more than 10% by weight, of other comonomer component.Specific examples of other comonomer components include fluorineatom-containing polymerizable monomers such as fluoroethylene,trifluoroethylene, chlorotrifluoroethylene,1,2-dichloro-1,2-difluoroethylene, 2-bromo-3,3,3-trifluoroethylene,3-bromo-3,3-difluoropropylene, 3,3,3-trifluoropropylene,1,1,2-trichloro-3,3,3-trifluoropropylene, and α-trifluoromethacrylicacid.

The content of the fluorine in the fluorine-containing copolymerobtained from the above monomer composition is preferably 60 to 70% byweight, more preferably 62 to 70% by weight, particularly preferably 64to 68% by weight. When the fluorine content is in the above-definedrange, the solubility of the fluorine-containing copolymer in solventswhich will be described later is high. Further, when thefluorine-containing copolymer is contained as a component, a thin filmhaving excellent adhesion, high transparency, low refractive index, andexcellent mechanical strength can be formed.

The molecular weight of the fluorine-containing copolymer is preferably5000 to 200000, particularly preferably 10000 to 100000, in terms ofnumber average molecular weight as determined using polystyrene as astandard. When the fluorine-containing copolymer having the above largemolecular weight is used, the resultant fluororesin composition becomesa suitable viscosity value and thus surely has suitable coatability.

The refractive index of the fluorine-containing copolymer per se is notmore than 1.45, preferably not more than 1.42, more preferably not morethan 1.40. When the refractive index is in the above-defined range, theformed thin film has favorable antireflection effect.

Further, a coating may be formed by exposing the fluorine-containingcopolymer and the resin to an actinic radiation optionally in thepresence of a photopolymerization initiator to perform polymerization,or by heating the fluorine-containing copolymer and the resin in thepresence of a thermal polymerization initiator to performpolymerization. In this case, the same resins as that described above inconnection with the antistatic layer may be used. Among these resins,dipentaerythritol hexa(meth)acrylate, pentaerythritoltetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, andcaprolactone-modified dipentaerythritol hexa(meth)acrylate arepreferred.

When the resin used contains three or more ethylenically unsaturatedgroups per molecule, in particular, the resultant fluororesincomposition can form a thin film that are very good in mechanicalproperties such as adhesion to the substrate and scratch resistance ofthe surface of the substrate.

The amount of the resin added is 30 to 150 parts by weight, preferably35 to 100 parts by weight, particularly preferably 40 to 70 parts byweight, based on 100 parts by weight of the fluorine-containingcopolymer. Further, the content of the fluorine based on the totalcontent of polymer forming components including the fluorine-containingcopolymer and the resin is 30 to 55% by weight, preferably 35 to 50% byweight.

When the addition amount or the fluorine content is in the above-definedrange, the refractive index layer has good adhesion to the substrate andcan exhibit good antireflection effect by virtue of high refractiveindex.

In forming the refractive index layer, if necessary, a suitable solventmay be used to modify the viscosity to a value which provides favorablecoatability as a resin composition, that is, a value in the range of 0.5to 5 cps (25° C.), preferably 0.7 to 3 cps (25° C.). In this case, anantireflection film having an excellent capability of reflecting visiblelight can be realized, and a thin film which is even, that is, free fromuneven coating, can be formed. Further, a refractive index layer whichis particularly excellent in adhesion to the substrate can be formed.

Means for curing the resin may be the same as that described above inconnection with the antistatic layer. When heating means is used as thecuring means, preferably, a thermal polymerization initiator which, uponheating, generates, e.g., radicals to initiate polymerization of thepolymerizable compound is added to the fluororesin composition.

The refractive index layer may also be formed by other conventional thinfilm forming means, for example, vacuum deposition, sputtering, reactivesputtering, ion plating, electroplating or other suitable means. Forexample, a coating of an antireflection coating material other than theabove material, an about 0.1 μm-thick very thin film or metal depositedfilm of MgF₂ or the like, or a deposited film of SiOx or MgF₂ may beformed as the refractive index layer.

Applications of Laminate

The anti-dazzling film according to the present invention is usable intransmission displays. In particular, the anti-dazzling film accordingto the present invention can be used in displays such as televisions,computers, word processors and the like, especially on the surface ofdisplays for high definition images, such as CRT and liquid crystalpanels.

EXAMPLES

The following Examples further illustrate the contents of the presentinvention. The present invention, however, is not to be construed asbeing limited thereto.

Preparation of Laminate

A 40 mm-thick triacetylcellulose (tradename: KC4U×2 MW, manufactured byKonica Corp.) was provided as a substrate. The following coating liquid1 or 2 for a transparent hard coat layer was bar coated. The coating wasthen dried to remove the solvent, and the dried coating was cured usingan H bulb in a UV irradiation apparatus (manufactured by Fusion UVSystems Japan KK) as a light source (integrated quantity of light: 99mj) to prepare a laminate comprising a transparent substrate having onits surface an about 7 mm-thick hard coat layer. The laminate using thecoating liquid 1 was designated as a laminate of Example 1, and thelaminate using the coating liquid 2 was designated as ComparativeExample 1.

Preparation of Coating Liquid for Transparent Hard Coat Layer

Coating Liquid 1 Fluorine-modified urethane acrylate 0.08 pt. wt.(MCF-350SF, manufactured by Dainippon Ink and Chemicals, Inc.)Pentaerythritol triacrylate (PET-30, 40 pts. wt. manufactured by NipponKayaku Co., Ltd.) Toluene 60 pts. wt. 1-Hydroxy-cyclohexyl-phenyl-ketone(Irgacure 1.6 pts. wt. 184, manufactured by Ciba-Geigy Ltd.)

Coating Liquid 2 Cyclohexane leveling agent (10-301, 0.8 pt. wt.manufactured by Dainichiseika Color & Chemicals Manufacturing Co., Ltd.)Pentaerythritol triacrylate (PET-30, 40 pts. wt. manufactured by NipponKayaku Co., Ltd.) Toluene 60 pts. wt. 1-Hydroxy-cyclohexyl-phenyl-ketone(Irgacure 1.6 pts. wt. 184, manufactured by Ciba-Geigy Ltd.)

Evaluation Test

The laminates of Example 1 and Comparative Example 1 prepared above weresubjected to the following evaluation tests. The results were as shownin Table 1 below.

Evaluation 1: Test on Degree of Adhesion of Coating

The laminate only on its hard coat layer face was cut with a cutterknife to form 100 cross-cuts (10 cross-cuts in longitudinal direction×10cross-cuts in transverse direction=100 cross-cuts). Next, for specimenshaving a size of 2.5 cm×10 cm, cross-cut Cello-Tape (manufactured byNichiban Co., Ltd.: cellophane adhesive tape) was rapidly attached anddetached. This procedure was repeated five times, and the degree ofadhesion of coating was expressed in m/100 wherein m represents thenumber of squares remaining unremoved among the 100 squares.

Evaluation 2: Measurement of Total Light Transmittance and Haze

The laminate was measured for the total transmittance and haze with areflectometer/transmissometer HR-100 (Murakami Color ResearchLaboratory).

Evaluation 3: Test on Strength

A pencil was pressed against the laminate under a load of 9.8 N, and thestrength of the laminate was evaluated in terms of the hardness of thepencil.

Evaluation 4: Scratch Resistance Test

A load of 4.9 N×2 was applied by a truck wheel CS-10F (manufactured byTABER INDUSTRIES) to the laminate by rotating the truck wheel by 100turns. A difference in haze between before and after 100-turn rotationof the truck wheel was then determined.

Evaluation 5: Test on Tackiness

The laminate was folded back to put the hard coat layer on top of thetransparent substrate, and the assembly was strongly rubbed with afinger by 10 times of reciprocation. The state after that was visuallyinspected for evaluation.

Evaluation 6: Test on Coefficient of Static Friction

The laminate was measured for the coefficient of static friction with asurface property measuring apparatus HEIDON (manufactured by ShintoScientific Company Ltd.). TABLE 1 Example 1 Comparative Example 1 Degreeof adhesion of 100/100 100/100 coating Total light transmittance (%)92.0 91.8 Haze (%) 0.2 0.3 Pencil hardness 2H 2H Scratch resistance test5.4 5.2 Tackiness Not tacky Tacky Coefficient of static friction 1.231.70

1. A laminate comprising a transparent substrate and a hard coat layerprovided on said transparent substrate, said hard coat layer beingformed of a cured product of a composition comprising afluorine-modified urethane acrylate and/or a polydimethylsiloxanerepresented by formula (I):

wherein A represents a polyether-modified acryl group or a polyethergroup.
 2. The laminate according to claim 1, wherein saidfluorine-modified urethane acrylate is such that all of hydrogen atomsin urethane acrylate have been substituted by a fluorine atom.
 3. Thelaminate according to claim 1, wherein the amount of the curablefluorine-modified acrylate and/or polydimethylsiloxane represented byformula (I) added is not less than 0.1% by weight and not more than 5%by weight based on the total weight of the hard coat layer.
 4. Thelaminate according to claim 1, wherein said transparent substrate istriacetylcellulose.
 5. The laminate according to claim 1, wherein saidhard coat layer further comprises an antistatic agent and/or ananti-dazzling agent.
 6. A laminate comprising the laminate according toclaim 1 and, provided on said laminate, at least one layer selected fromthe group consisting of an antistatic layer, an anti-dazzling layer, anda refractive index layer.
 7. A display comprising the laminate accordingto claim 1.